The pathologist stood in the kitchen on his 40-acre farm and cut the crust from a ham and cheese sandwich for his 7-year-old son’s packed lunch. He took a swig of his morning coffee. He’d been up late answering calls, hustling to launch a clinical trial to test blood plasma as a possible treatment for covid-19, hashing out the details between rides on his Peloton stationary bike and taking rifle shots at nuisance groundhogs.